When making movies and television shows, the camera lenses used during production will often use motor drives to control focus, T-stop, zoom focal length, etc. Currently, lens drive motors are attached to the iris rods (AKA lens support rods) of motion picture and video cameras via closed clamps that are sized to match one of various sizes of iris rods used by the various manufacturers to support lenses for motion picture and video cameras (e.g., Panaflex®, Arriflex®, Red One®, etc.). In order to install or remove such a mount with a closed clamp, it is often necessary to remove other items mounted on the iris rods, such as matte boxes. Furthermore, different cameras with different-sized diameters of iris rods, which can be 15 mm, 19 mm and ⅝″ —depending on the manufacturer and model of camera, require the use of lens drive motor mounts with appropriately-sized closed clamps in 15 mm, 19 mm and ⅝″ diameters. As such, this requires a camera rental company to maintain a large inventory of different sizes of clamps.
One attempt to address a similar problem with matte box mounts is found in U.S. Pat. No. 6,450,465 to Eslick, which discloses a multi-jaw clamp capable of attaching to various sized iris rods of a professional movie camera. The multi-jaw clamp includes two housings that each hold a cylinder with three circular sections in the sides of the cylinders that are rotatable to change the size of the circular opening for the iris rod to which the clamp can attach. The two housings contain hinge means for opening and closing the clamp and at each free end of the housings is a means for closing the clamp and locking the clamp in position around the iris rod. As such, a multi-jaw clamp can attach to three possible iris rod diameters with the same components. However, this design using inserts is mechanically complex and difficult to manufacture. The large and cumbersome design is also unsuited for mounting in tighter locations used for mounting some equipment.
What would be desirable is a simple, compact design for a lens drive motor mount that overcomes the problems with the prior art.